Do Risk-Reducing Surgeries Benefit Young BRCA Carriers?

Patients with BRCA-mutations and a history of early-onset breast cancer benefited from risk-reducing surgeries, according to new data presented at the San Antonio Breast Cancer Symposium (SABCS) 2024.

Having a risk-reducing mastectomy or salpingo-oophorectomy was associated with significantly improved overall survival and disease-free survival in BRCA-mutation carriers who had been diagnosed with a first breast cancer at age ≤ 40 years.

“This global study provides the first evidence that risk-reducing surgeries improve survival outcomes among young BRCA-mutation carriers with a prior history of early-onset breast cancer,” study investigator Matteo Lambertini, MD, PhD, oncologist with the University of Genova-IRCCS Policlinico San Martino Hospital in Genoa, Italy, said in a statement from the SABCS, where he presented the findings. “Considering the unique traits and needs of this younger population, and their high risk for secondary malignancies, it is critical to understand how risk-reducing surgeries affect patient outcomes, so that the risks and benefits of these procedures can be carefully weighed.”

“We hope these findings may help to improve the counseling on cancer-risk management strategies for BRCA carriers with young-onset of breast cancer below the age of 40 years,” Lambertini added during a press briefing. 

Various risk-reducing strategies, including risk-reducing surgeries, are recommended for BRCA-mutation carriers without a prior history of cancer, but the impact of these surgeries among younger populations with a history of early-onset breast cancer has been less clear.

The new findings come from the BRCA BCY Collaboration, an international, multicenter, retrospective cohort study of 5290 patients with likely pathogenic/pathogenic germline BRCA1 and/or BRCA2 mutations who were diagnosed with stages I-III breast cancer at ≤ 40 years. The risk-reducing mastectomy analysis included 2910 patients (55%) who underwent the surgery less than 1 year from diagnosis and 2380 who opted not to have the surgery. 

Primary endpoint was overall survival, and disease-free survival and breast cancer-free interval were secondary endpoints. Overall survival models were adjusted for the development of distant recurrences or second primary malignancies.

During median follow-up of 5.1 years, patients who underwent risk-reducing mastectomy had a 35% lower risk of dying (adjusted hazard ratio [aHR], 0.65) as well as a significant improvement in both disease-free survival (aHR, 0.58) and breast cancer-free interval (aHR, 0.55). The improved outcomes were seen in both BRCA1 and BRCA2 carriers, Lambertini reported. 

The risk-reducing salpingo-oophorectomy analysis included 2782 patients who underwent this surgery a median of 3 years from diagnosis and 2508 who did not. 

During median follow up of 4.9 years, risk-reducing salpingo-oophorectomy was associated with a 42% lower risk for death (aHR, 0.58) as well as an improvement in both disease-free survival (aHR, 0.68) and breast cancer-free interval (aHR, 0.65).

For risk-reducing salpingo-oophorectomy, there was an interaction based on breast cancer subtype and BRCA mutation.

“Specifically, the benefit of risk-reducing salpingo-oophorectomy was greater for patients with BRCA1 pathogenic variants and for those with triple-negative disease, as compared to those with BRCA2 pathogenic variants or luminal disease,” Lambertini reported.

Overall survival results were similar in patients who underwent one or both surgeries.

Briefing moderator Kate Lathrop, MD, with the University of Texas Health Science Center at San Antonio, noted that this study provides valuable information for counseling younger patients. Having datasets like this helps us give patients “potentially our best estimate of the amount of reduction of risk you could have by having the surgery now.”

In an interview with Medscape Medical News, Freya Schnabel, MD, director of breast surgery at NYU Langone Health’s Perlmutter Cancer Center, emphasized the importance of early, well-informed decision-making upfront at the time of diagnosis in this patient population.

The benefit of “risk-reducing oophorectomy cannot be over emphasized, even in the presence of a known breast cancer because, as my colleagues and I say — we don’t want to cure their breast cancer and then have them die of ovarian cancer,” said Schnabel, who was not involved in the study.

In terms of prophylactic contralateral mastectomy, Schnabel noted that BRCA-mutation carriers have a “very high” risk for a second primary breast cancer. In her experience, “that’s what drives patients frequently at the time of diagnosis to have bilateral mastectomy because who wants to go through this more than once?” 

This is especially true for BRCA1 carriers who have a higher risk for triple-negative breast cancer, which is associated with a worse prognosis and is harder to treat, Schnabel said. 

“For these patients, having surgery prevents the patient from getting into a situation where their second primary tumor winds up being biologically more aggressive and then affects their survival,” Schnabel said.

The study was supported by the Italian Association for Cancer Research and the European Society for Medical Oncology. Lambertini reported advisory roles for Roche, Lilly, Novartis, AstraZeneca, Pfizer, Seagen, Gilead, MSD, Exact Sciences, Pierre Fabre, and Menarini. Lathrop consults for TeraSera Pharmaceuticals. Schnabel had no relevant disclosures.